Pipe cutter



June 18, l957 G. P. ELLIS 2,796,123

PIPE CUTTER Filed Nov. 16. 1954 i BY ATTORNEYS.

United States Patent C PIPE CUTTER Guy Paul Ellis, Lake Charles, La.

Application November 16, 1954, Serial No. 469,086

11 Claims. (Cl. 164-.6)

This invention relates to improvements -in outside pipe cutters of the type employing anchoring means set by upward movement of .the pipe cutter in applying an inward force to the .cutting knife, and more particularly :to `a m-eans for releasing the .anchoring means from the pipe to permit removal of the pipe cutter in the event it becomes necessary to remove the cutter before lthe `cut is completed.

In cutting oif and removing sections of pipe stuck in a well, it sometimes happens that it is impossible to cornplete a cut and it is necessary to remove .the pipe cutter while leaving the string of pipe in .the hole. In pipe cutters of the .type shown and described in Patent No. 2,202,985, issued to I. T. Ellis June 4, 1940, it is necessary `to release the slips anchoring the knife carrier to the pipe to :be out before the pipe cutter can be removed. In this pipe cutter, it is .contemplated that the cutter 'will be moved .downwardly from the point of the attempted cut until the upper threaded shank of :the slip carrier is threadedly engaged with an internally threaded collar positioned immediately above the slip carrier. This form of releasing means has several disadvantages. For in stance, :with the pipe cutter suspended from a long .string of tubing, it is quite difficult for vthe :operator to make up the threaded connection between the slips and the collar sthereabove.l VUsually the pipe cutter is run into the hole las far as possible before .a out is made and thus` there is very little 'leeway for downward movement :of Ithe pipe cutter to effect release of the slips.

lIt is an object of this invention to provide apipe cutter in which initial upward movement of the body of the pipe cutter will anchor the cutter on the pipe Vto be cut and render effective a means for urging the cutting knives ytoward the pipe and in which a further upward move- Ament `of the body will release the anchoring means. p

Another :object of this invention is :to provide .a pipe cutter in which initial upward movement of the body of the cutter anchors slipson the pipe sto resist upward movement of a knife carrier, a .continued upward Ymzovef ment `of the body relative -to the knife carrier renders effective a means for exerting `an inward force Aon' the knives, and stillV further upward movement of the body relative to the carrier effects release of the .anchoring means to permit `withdrawal of the pipe cutter. f

Another object is to provide a pipecutter in which initial upward movement of the cutter body anchors .slips to the pipe to be cut, still further upward movement of the body renders etfective aV means for urging the knives of the cutter inwardly, and a still further upward movement of the body releases the `slips in which provision is Amade for movement lofthe body a slight distance in excess of that necessary sto render effective |the knife urging means without releasing the slips. y

Another object is to provide a pipe cutter of :the type disclosed in the Ellis patent with means lfor releasing the slips upon upward movement of the pipe cutter.

lOther objects, features .andadvantages of thisinvention willbe apparent from the 4following descriptiontaken Patented June 18, 1957 ice in connection with :the accompanying `drawings and the appended claims.

In the drawings wherein there is set forth by way of example and illustration one embodiment of this invention;

Fig. 1 is a vertical cross .section through a cutter device constructed in accordance with .this invention, showing in elevation a pipe about to be cut, the parts being illustrated in Ithe position which they occupy before the `cutting operation begins;

Fig. 2 is a View similar to Fig. l but lwith .the parts in the posi-tion they occupy during the cutting operation;

Fig. 3 is a view similar to Fig. 1 but showing the parts in the position they Ioccupy after .the anchoring means has been released from the pipe;

jFigli is a partial horizontal cross section taken along the lines 4-4 of Fig. 1; and

Fig. 5 is a partial horizontal cross section taken along the lines 5 5 of Fig. l.

.The outside cutter illustrated includes slips which are anchored `to the pipe to be cut by initial upward movement of the body of the tool so as to limit upward movement of rtl-le knife carrier. Further upward movement of the body frees the knife carrier from the body of the tool `and renders effective the means for urging the knives of the tool inwardly towards the pipe as by a wedge inember and spring as shown in the drawings. The knife oarrier is held in spaced relation with the anchoring means by a :telescoping joint ywhich is held in extended position iby shear pins, but which upon further up-ward movement of the body relative .to the `anchoring means .will collapse and limit the wedge ring and slips .ofthe anchoring means to separate, thus permitting the cutting tool to be removed from the hole in the event it is impossible to complete: the cut.

Referring p now more in detail Ito the drawing, the numeral .10 designates a section of pipe to be cut. It -will be understood that for some reason this pipe .cannot be pulled from the hole in :the usual manner and it is neces- Vsaryto remove the pipe' section by section utilizing a cutting tool such as shown in the drawings.

The cutting tool includes a tubular body 11 which may f be suspended from a string of .tubing in the usual manner :and is provided'at its lower end with a guide shoe 112. Shoe 12 4may have la reduced threadedsection 12a which is threaded into the bore of body 11 with the end of reducedl tending annular llange members 17 and 18 which co' operate with inwardly projecting pins 14 on body 11 to limit sliding movement of slip carrier 15. The lowermost flange 18 retains segmental slips 1'9 which depend from slip 4carrier 15 in a position to be engaged by wedge ring 16 upon upward movement of body 11. The.v uppermost iiange 17 4on slip carrier 15 will prevent the slips from following wedge ring 16 downwardly upon: collapsing of the force transmitting meansl indicated generally at 20 between'wedge ring 16 andthe knife carrier 21 when the tool is to be 'pulled from vthe well' without removingthe pipe to be cut, as best shownin Fig. 3.

wedge ring 16 relative to slips 19 will set the slips onr pipe 10. The pipeto be -cut may or'may not havetool joints such as indicatedat 19a, but if such 'toot joints :f are present, it is preferred that slips v19` have a setwhich will tend to engage ,such tool joint instead of the pipe upon` Slips 19' and wedge ring 16. are provided withfl upwardly and outwardly slanting cooperating'wedge fsu'r faces 19a and 16n`which upon upward movement of upward movement of the tool. Where such a tool joint is not present, slips 19 will have a set which will tend to engage the pipe 16 immediately upon upward movement of body 11.

Knife carrier 21 is provided with one or more depending cutting knives 22 which are hinged for movementV towardV and away from the pipe yto be cut about hinge pins 23. Knife carrier 2l is initially held in the position shown inFig. l by means of a shear pin 24 to hold the knife 22 in non-cutting position. As best shown in Fig. 4, knife carrier 21 is permitted tr:- slide vertically "in body il while being held against rotation within the body by means of splines 25 formed 'in body 11. Sliding movement of cutter carrier 21 downward relative to body 11 is limited by means of cooperating Shoulders 26 and 27' on the, body and cutter carrier respectively to limit `the amount of inward force which may be exerted upon knives 22 during the cutting `operation as will hereinafter more fully appear.

Upward movement of cutter carrier 21 is transmitted to wedge ring 16 by a force transmitting means which preferably includes a resilient meanssuch as spring 2S, a bearing 29, and a means for rendering ineffective the forcel transmitting means such ns telescoping members 30 and 31 held in extended position by shear pins Shear pin 32 should be stronger than shear pin 24 so that pin 24 may be sheared and normal cutting operations performed with the telescoping members 33 and 31 held in extended posit-ion. If for some reason the cut cannot be completed, then further upward movement of body 11 and cutter carrier 21 will first compress spring 23 and then shear pins 32. Upon shearing of lpins 32, telescoping member 31 is free to telescope within member 3d and move wedge ring "lo downwardly to the position shown in Fig. 3. As best shown in Fig. 3, the inwardly projecting pins 14 on body 11 will cooperate with outwardly projecting harige 17 on slip carrier 15 and maintain slips 19 spaced above wedge ring 16 with members 3).and 31 telescoped so as to permit the tool to be raised without the anchoring parts engaging to set the slips. Bearing 29 permits relative rotation of cutter 21l and the anchoring means while the pipe Ais being cut. Spring 2S .permits the body to be raised slightly more than necessary to etfect operation ofthe means applying an inward force to the cutting knives without shearing shear pins 32. This will permit an operator to be certain that he has a sufficient upward movement of body 11 to properly operate the cutting knives without such distances being too critical.

The means for urging the cutting knives 22 inwardly while a cut is being made is provided by a wedge ring 33 having a wedge surface 34 which cooperates with a wedge surface 35 on the outward edge of cutting knife 22 to urge the knife inwardlytoward the pipe to be cut. As best shown in Fig. 4, wedge ring 33 is slidable within body 11 and held against rotation relative thereto by splines 25 in body 11. A spring 36 is positioned between wedge ring 33 and shoulder 13 provided by the reduced threaded section 12a of guide shoe 12. Spring 36 should be somewhat weaker than spring 28 so that it may be compressed as best s'hown in Fig. 2 until' shoulders 26 and 27 are lin abutment to apply a constant inward force to knife 22 with but small compression of spring 28.

In operation the cutting tool is lowered into the well with the parts in the position shown in Fig. 1. While in this position, the springs 36 and 23 are not under compression and knife carrier 21 is held in elevated position by shear pin 24 so that knife 22 is lheld in noncutting position. The slips are lightly resting upon wedge ring 16 but `this will not interfere with lowering of the tool about. pipe 10. When the depth is reached at which I a cut is to be made, the cutter is pulled upwardly a slight distance until the anchoring means is set on the pipe by the Wedge. acti-on between Wedge ring 16 and the slips 19., A further upward pull shears pin 24 and moves body 11 upwardly relative to cutter carrier 2l and the anchoring means. Such further movement will bring wedge ring 3.3 into engagement with knife 22 and compress spring 36 to apply an inward force to knife 22. At this point, shoulders 26 and 27 on body 11 and cutter carrier 21, respectively, will engage and any further upward movement of thc body will move the cutter carrier 21 upwardly along with wedge ring 33. rThis will prevent any additional compression of spring 36 so that a constant predetermined inward force may be placed upon knife 22 while the cutis being made.

As will be clear to those skilled in the art, the operator gauges his pull as to the degree of force used so that he will Shear the pin 2'4 but will not shear the pin 32 by means of watching the customary weight indicator attached to the lifting equipment at the surface of the earth during thc time that he is applying the force to shear the pin 32. When that pull increases beyondy the weight of the tool itself and the pipe by whichv it is suspended by an amount greater than` that sufficient to shear the pin 211i but less than that which would be rcquired to shear the pin 32, the operator will know that the pin 2d. should be be sheared and in practice this result may be accomplished with a high degree of assurance. Obviously the pin 32 could not be sheared until sulicient force in addition to the weight of the tool and suspended pipe is applied by the `hoisting equipment at the surface of the earth,v as indicated by the weight indicator, to overcome the shear strength of the pin 32. The distance traveled may be ignored because the travel would bey limited by the pin 32 until the force becomes great enough to shear the pin 32. Obviously if the force is kept below that necessary to shear the pin 32, the travel cannot be sufcient to cause such shearing.

The cutting tool may then be rotated and as it rotates spring 36 will urge wedge ring 33 into engagement with knife 22 and cause the knife to cut the pipe. When the cut is completed, the severed upper section of pipe may be removed frorn the hole by removing the Cutter, this severed portion being heldin the cutting device by the anchoring means.V During the cutting operation, a tension may be taken on the pipe to be cut which is greater than the weight of the section that will be severed so that when the cut is completed there will be substantially no force exerted on the knife by the piece of pipe severed. Instead as soon as the cut is completed, this will be indicated to the operator by relief of the tension which he has been-maintaining on the stuck pipe during the cutting operation.

In the event it should be impossible for some reason to complete the cut, the cutting tool may be withdrawn by the simple expedient of further raising the cutting tool relative to the slips 19. Such further raising will rst compress spring 28 and then shear pins 32 whereupon telescopingV elements 30V and 31 will telescope together permitting the anchoring parts 16 and 19 to move apart releasing slips 19 from the pipe. When this has been accomplished, the parts will be in the position illustrated in Fig. 3 and the tool may be withdrawn from the hole; Referring particularly to the knife 22 of Fig. 3, it will be seen that the cutting point has been broken olf. This will usually occur when the body is moved upwardly in shearing pins 32 as cooperating shoulders 26 and 27 move cutter support 21 upwardly with the body and as the knife is still being urged into cut 37 in the pipe by wedge ring 33, the point of the knife may be broken off.

Some further breakage of the knife may occur as it passesv over collars on the string in withdrawing the tool but the only damaged part will be the knife 22 which may be replaced after the cutting tool is withdrawn.

It will be apparent from the foregoing that there has been provided a cutting tool which may be withdrawn when it is impossible to complete a cut by simply lifting up on the cutting tool. It is not necessary to lower or rotate, attempt to thread or otherwise tit parts together to yunseat ther anchoring means from the pipe. It will also be apparent that such a tool has been provided in which the desirable feature of a constant tension on the knives urging them toward the pipe to be cut has been retained. There has also been provided a cutting tool in which successive increments of upward movement of the body of the cutting tool will set the anchoring means, move the knives into cutting position, and if it is impossible to complete the cut, release the anchoring means, in which means is provided to allow an upward movement of the tool slightly in eXcess of thatnecessary to set the slips and move the knives into cutting position without unseating the anchoring means, thus providing a safety margin for the operator in the normal operation of the tool.

From the foregoing it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth, together with other advantages which. are obvious and which are inherent to the apparatus.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and Vsubcornbinations- This is contemplated by and is within the scope of the claims.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth `or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

The invention having been described, what is claimed 1. In an outside pipe cutter having a body and a cutting knife carried by the body, the improvement which resides in the combination therewith of means for selectively urging the cutting knife inwardly toward a pipe to be cut upon upward movement of the body, said urging means including means for anchoring the cutter on a pipe to be cut and resisting further upward movement of the body'to render eective the urging means, and means for rendering ineffective the anchoring means upon further upward movement ofthe body to permit the cutter to be removed from the pipe.

2. In an -outside pipe cutter having a body, a knife carrier slidably and non-rotatably mounted in the body, and means for urging a knife mounted on the carrier inwardly toward a pipe to be cut upon upward movement of the body `relative to the carrier, the improvement which resides in the combination therewith of anchoring means having cooperating parts which when engaged grip the pipe, force transmitting means between one of said parts and the carrier, said parts engaging upon upward movement of the carrier and gripping the pipe to resist further upward movement of the carrier and render effective the knife urging means, and means rendering ineffective the force transmitting means upon further upward movement 4of the carrier to thereby permit the anchoring parts to separate and release the anchoring means from the pipe.

3. In an outside pipe cutter having a body, a knife carrier slidably and non-rotatably mounted in the body and means for urging a knife mounted on the carrier inwardly toward a pipe to be cut upon upward movement of the body relative to the carrier, the improvement which resides in the combination therewith of anchoring means having cooperating parts which when engaged grip the pipe, force transmitting means between one of said parts and the carrier, `said parts engaging upon upward movement of the carrier and gripping the pipe to resist further upward movement of the carrier and render effective the knife urging means, said force transmitting means including resilient means to permit the body to be moved upwardly relative to the anchoring means slightly more than necessary to place the desired inward force on the cutting knife, and means rendering ineffective the force transmitting means upon further upward movement of the carrier to thereby permit the anchoring parts to separate and release the anchoring means from the pipe.

4. In an outside pipe cutter having a body, a knife car- CFI rier slidably and non-rotatably mounted in the body, and

means for urging a knife mounted on the carrier inwardly toward a pipe to be cut upon upward movement of the body relative to the carrier, the improvement which resides in the combination therewith of anchoring means having a first part mounted for limited sliding movement in the body and a second part slidably mounted in the body, force transmitting means between the second part and the carrier, said parts ycooperating to grip the pipe l upon upward movement of the carrier to resist further upward movement of the carrier and render effective the knife urging means, and means rendering ineffective the force transmitting means upon further upward movement of the carrier to thereby permit the anchoring parts to separate and release the anchoring means from the pipe.

5. In an outside pipe cutter'having a body, a knife carrier slidably and non-rotatably mounted in the body, and means for urging a knife mounted on the carrier inwardly toward a pipe to be cut upon upward movement of operation of the cutter, said telescoping members rendering the force transmitting means ineffective upon shearing of the shear means by further upward movement of the carrier to thereby permit the anchoring parts to separate and release the pipe.

6. In an outside pipe cutter having a body, a knife carrier slidably and non-rotatably mounted in the body, means including a resilient member urging a knife mounted on the carrier inwardly toward a pipe to be cut upon upward movement of the body relative to the carrier, and a first shear means holding the cutter knife in non-cutting position prior to such upward movement, the improvement which resides in the combination therewith of, anchoring means having a first part mounted for limited sliding movement in the body and a second part slidably mounted in the body, and force transmitting means between the second part and the carrier including telescoping members held in extended relationship by second shear means which is considerably stronger than said first shear means, said parts cooperating to grip the pipe upon upward movement of the body and carrier to resist further upward movement of the carrier relative to the pipe to render ineffective the first shear means and render effective the knife urging means for normal operation of the cutter. still further upward movement rendering ineffective the second shear means to permit telescoping of the telescoping members and render ineffective the force transmitting means whereby the first and second anchoring parts may separate and release the anchoring means from the pipe.

7. The cutter of claim 6 wherein the force transmitting means includes a resilient .means which is stronger than the knife urging resilient means to permit the body to be raised relative to the anchoring means adistance slightly greater than necessary to render effective the knife urging means without shearing the second shear means.

8. An outside pipe cutter comprising, a body, a knife carrier slidably and non-rotatably mounted in the body, anchoring means including a first part slidable within limits in the body and a second part moved into engagement with the first part by upward movement of the carrier to set the anchoring means on the pipe, force transmitting means between the second part and the carrier whereby the anchoring means when set will resist upward movement of the carrier, means for applying an inward force to a knife mounted on the carrier upon upward movement of the body after the anchoring means has been set, and means rendering ineffective said force transmitting means upon further upward movement of the body to permit said anchoring parts to separate a distance sufficient to release the anchoring means from the pipe.

9. An outside pipe cutter comprising, a body, a knife carrier slidably and non-rotatably mounted in the body, anchoring means including a first part slidable within limits in the body and a second part moved into engagement with the tirst part by upward movement of the carrier to set the anchoring means on the pipe, force transmitting means between the second part and the carrier whereby the anchoring means when set will resist upward movement of the carrier, means for applying an inward force to av knife mounted on the carrier upon upward movement of the body after the anchoring means has been set, said force transmitting means including resilient means to permit the body to be moved upwardly slightly more than necessary to render the means urging the knife inwardly effective, and means rendering ineffective said force transmitting means upon further upward movement of the body to permit said anchoring parts to separate a distance sufficient to release the anchoring means from the pipe.

10. An outside pipe cutter comprising, a body, a knife carrier slidably and non-rotatably mounted in the body, anchoring means including a first part slidable within limits in the body and a second part moved into engagement with the first part by upward movement of the carrier to set the anchoring means on the pipe, force transmitting means between the second part and the carrier whereby the anchoring means when set will resist upward movement of the carrier, means for applying an inward force to a knife mounted on the carrier upon upward movement of the body after the anchoring means has been set, said force transmitting means including telescoping parts held in extended position during the cutting operation, and means for rendering ineffective said hold- 8 ing means upon further upward movement of the body to permit said anchoring parts to separate a distance siiicient to release the anchoring means from the pipe.

1l. An outs-ide pipe cutter comprising, a body, a knife carrier having a depending knife slidably and nonyrotatably mounted in the body, a first shear pin securing the carrier to the body with the knife in non-cutting position, anchoring means including a first part slidably mounted in the' body above the carrier and a second part moved into' engagement with the first part by upward movement of the carrier to set the `anchoring means on -the pipe, a force transmitting connection between the carrier and the second part whereby the anchoring means when set will resist upward movement of the carrier, means for applying an inward force to said knife rendered effective by upward movement of the body after the anchoring means has been set, said force applying means including a wedge member positioned below the knife and resilient means between sa-id wedge member and an upwardly facing shoulder in `the body, and cooperating abutment parts on the carrier and body limiting downward movement of the carrier yrelative to the body to limit the force Aapplied to the knife by the resillent means, said torce transmitting connection including a second resilient means which is stronger than the force applying resilient means and telescoping parts held in extended relationship 4by a second sheai pin stronger than said carrier shear pin, said force transm-itting means rendered ineffective by shearing of said secon-d shear pin upon further upward movement of the body to permit the anchoring parts to separate' and release the anchoring means.

References Cited in the file of this patent UNITED STATES PATENTS 1,530,636 Anderson et al Mar. 24, 1925 1,767,018 Segelh'orst I une 24, 1930 2,202,985 Ellis June 4, 1940 

